Clash-of-clans – If I never battle in Clash of Clans and I have zero trophies will I get atacked at a higher townhall

You can be attacked at any time where your shield is not active.

If you look at the top of the screen you will see an information label that says "Shield". At any time that this says "None" you can be attacked by other players (excluding times where you are actively playing - i.e. the game is open on your device).

When you first start the game you are given a free shield for several days to give you time to build your defences up. Your shield can later be reactivated:

• At any time for a set fee of gems (1 day, 2 day and 1 week options)
• If you are attacked by another player and lose 40% of buildings or town hall the shield is reactivated for 12 hours (war attacks do not count)
• If you are attacked by another player and lose 90% of buildings the shield is reactivated for 16 hours (war attacks do not count)

Attacking another player in multiplayer disables any shield you have.

You can also never be attacked whilst you have the app open.

Unfortunately, this is not possible. The link is done on the SuperCell servers, and there's no way to unlink an account from a Google+ (Android) or Game Center account (iOS).

You will need to create a new Google+ account to link to your village.

Just FYI, there's some information I found on Google that suggests you can unlink it by going into Google+ settings. I just tried these suggestions with a test village of mine and can co firm that process doesn't work.